1. Field of the Invention
The present invention is directed to a driving circuit and more particularly, to a driving circuit having electrostatic protection capability and capable of reducing an equivalent time constant.
2. Description of Related Art
Typically, the way for a driving circuit to generate driving voltages in an Integrated Circuit (IC) is to directly connect a gamma resistor string to digital-to-analog converters (DACs) to provide the DACs with a plurality of reference voltages, such that the driving voltages are generated by the DACs. Gamma voltages are divided to a plurality of reference voltages required by the internal of the driving circuit using the gamma resistor string, and the reference voltages are transmitted to the corresponding DACs. The DACs converts pixel data to analog signals (driving voltages) according to each of the reference voltages and outputs the analog signals (driving voltages) to an output-stage circuit. The output-stage circuit gains the driving voltages and outputs the gained driving voltages to a display panel.
However, during a process of electrostatic discharge test, manufacturing, or usage of the IC, an over large electrostatic energy is commonly produced and flows in the internal of the driving circuit IC. If such electrostatic energy is not vented by an adaptive electrostatic discharge protection circuit, elements thereof may be damaged or even worse, the IC may be directly burned, which results in a demand of electrostatic discharge protection to improve the protection capability for resisting the electrostatic.